Cracking
Definition
Cracks of various lengths and depths.

Causes
- Inappropriate paint system used on thermoplastic substrates (direct use of polyester body fillers/ fillers, wash primers/ synthetic resin products on TPA) which caused the TPA surface to soften
- Refinished paintwork insufficiently cured (too little or no hardener used)
- Inappropriate paint system used:
Wash primer overcoated with polyester products
Synthetic resin or nitro-cellulose paints overcoated too early - Cracks on plastic parts:
- see entry on "Faults in painting plastics"
- Exposure to strong UV radiation, extreme temperature fluctuations
- Flash-off time too short in wet-on-wet process
- Total film build too high

2fache Vergrößerung
- Apply a suitable paint system to the substrate.
- Ensure correct hardener quantities.
- Use correct paint system.
- Plasticize materials (see entry on "Faults in painting plastics").
- There are no complaints about "cracking" with regard to present Glasurit automotive refinish products.
- Respect recommended flash-off times.
- Check paint system and film thickness of old paintwork and sand down or strip down, if necessary.
Please note: For older car models, use refinishing processes for solvent-sensitive paintwork. Classic Car system S 1a.
REPAIR
Sand down to the "sound" layers. Refinish using the recommended undercoats and topcoats.